Structure, chaperone-like activity and allergenicity profile of bovine caseins upon peroxynitrite modification: New evidences underlying mastitis pathomechanisms

Mastitis, an inflammatory reaction frequently develops in response to intra-mammary bacterial infection‌‌, may induce the generation of peroxynitrite (PON)‌ which is a highly potent reactive oxygen and nitrogen species. Caseins as the intrinsically unfolded proteins seem feasible substrates to react with PON. Therefore, in the current study, structural and functional aspects of both β-casein (β-CN) and whole casein fraction (WCF) were evaluated after PON modification, using a variety of techniques. Modification of the bovine caseins with PON results in an important enhancement in the carbonyl, nitrotryptophan, nitrotyrosine and dityrosine content of these proteins‌. The results of fluorescence and far UV-CD assessments suggested significant structural alteration of caseins upon PON-modification. The chaperone-like activity of β-casein was significantly altered after PON modification. The results of scanning electron microscopy suggest that bovine caseins display unique morphological features after treatment with PON. Also, the PON-modified caseins preserved their allergenicity profile and displayed partial resistance against digestion by the pancreatic proteases. Ascorbic acid, an important antioxidant component of milk, was also capable to significantly prevent the PON-induced structural damages in bovine milk caseins. In conclusion, our results suggest that PON may have significant role in the structural and functional alteration of milk caseins. Also, the PON-induced structural damaging effects of caseins might be effectively prevented by a sufficient level of milk antioxidant components particularly by ascorbic acid.

Frequency and Risk Factors of Penicillin and Amoxicillin Allergy in Suspected Patients with Drug Allergy

BACKGROUND

Unconfirmed beta-lactam allergy is a significant public health problem because of the limitations it imposes in drug selection. In this study, we aimed to evaluate patients referred for beta-lactam allergy to determine the frequency of confirmed beta-lactam allergy and identify some risk factors.

METHODS

In a prospective cohort study, all referred patients to Immunology, Asthma and Allergy Research Institute in Tehran University of Medical Sciences (between 2007 - 2009) who suspected to have beta-lactam allergy were entered into this study based on having the inclusion criteria. Follow-up was performed 6 - 8 years after the final diagnosis. Diagnosis of beta-lactam allergy relies on thorough history and specific IgE measurements (ImmunoCAP), skin prick testing (SPT), intradermal testing (IDT), patch testing, and oral drug challenge test.

RESULTS

Fifty-one patients with mean age of 24.5 (±18.5) years were enrolled in this study. Based on workups, beta-lactam allergy was confirmed in 16 (31.4%) patients, suspicious in 22 (43.1%) patients and ruled out in 13 (25.5%) patients.  During the follow-up, 3 patients with suspicious drug allergy consumed the culprit drug with no reaction so allergy was finally ruled out in 16 (31.4%) patients. Age, sex, atopy and family history of drug allergies were not significantly different between the patients with confirmed or ruled-out diagnosis of penicillin and amoxicillin allergy.

CONCLUSION

At least up to one-third of patients with a history of beta-lactam allergy are proven to be safe using the drug. Also, a clear protocol consists of serum sIgE assay and SPT can be helpful to the physicians in the health care system.

Cow's milk anaphylaxis in children first report of Iranian Food Allergy Registry

Cow's milk anaphylaxis is the most common food-induced anaphylaxis in Iranian children. The clinical and laboratory findings of cow's milk anaphylaxis are evaluated in this study. All children who had experienced cow's milk anaphylaxis and had been referred to Immunology, asthma and allergy research center during a 5-year period were considered. After fulfilling a questionnaire, patients underwent measurement of total IgE and cow's milk-specific IgE by Immunocap test and Skin prick test (SPT) with cow's milk extract. Patients with a convincing history and one positive cow's milk-specific IgE test (SPT or Immunocap test) and patients with both positive tests were enrolled, in this study.Out of 49 patients, 59.2% were male. Patients' mean age was 5 years old and their mean age at the time of first attack was 5.7 months (SD = 4.3). Most of the patients have experienced more than one episode of anaphylaxis (79.5%) and in 85.7% of all cases, first attack occurred during the first year of life. Severity grading 1-5 were 2%, 6.1%, 18.4%, 69.4%, 4.1% respectively. Most common manifestations were cutaneous 98%, Respiratory 91.8%, Gastrointestinal 55.1%, Cardiovascular 46.9% and neurologic 46.9% signs and symptoms respectively. Twenty four patients showed positive SPT. Mean total IgE was 239.6±3.3 (IU/mL) and mean cow's milk-specific IgE was 19.28±27.2 (IU/mL). Most patients showed reactions only after ingestion of cow's milk or after dairy foods (81.6%).It is concluded that cow's milk anaphylaxis may happen early in life. Regarding the severity of attacks and remarkable number of patients with several attacks, poor knowledge about this disorder is evident.

Common causes of anaphylaxis in children: the first report of anaphylaxis registry in iran

BACKGROUND

: Anaphylaxis is an acute, systemic, and potentially fatal allergic reaction. Many things can cause anaphylaxis potentially but some agents are more common like some foods (milk, egg, soy, wheat, peanut, tree nut, shellfish, and fish), insect stings, medications, latex, and food-dependent exercise-induced anaphylaxis. The goal of this study is to show the common causes of anaphylaxis among the children with anaphylaxis history who were referred to the Immunology, Asthma and Allergy Research Institute (IAARI) during a 4-year period (2005-2009).

METHODS AND MATERIALS

: During those 4 years, we registered all children (<14 years old) with a history of anaphylactic reaction. To prove the cause of anaphylaxis, we performed skin prick tests with suspected agents according to their history and measured specific IgE against them by the ImmunoCAP test. Recognition of common allergens was based on having a positive history for 1 allergen and positive skin prick test or specific IgE for that at the same time, or having positive results from both tests when the allergen was unclear. Idiopathic anaphylaxis was a reaction when any known allergen and positive tests were not obtained.

RESULTS

: One hundred ninety-three nonfatal anaphylactic attacks among 63 children were recognized. In total, the most current cause of anaphylaxis in children was food (89.7%). Milk (49.3%) and wheat (26.1%) were the most common. Other foods were egg (8.7%), nuts (2.8%), and spices (2.8%). Six children (8.7%) were sensitive to multiple food allergens like milk, egg, and wheat. Five (7.1%) of 63 patients had anaphylactic attack because of stinging. Wasp was the trigger in 3 (4.3%) of them and honeybee was the cause in 1 (1.4%). The last one was because of unknown hymenoptera. There were 2 idiopathic cases of all 63 patients.

CONCLUSIONS

: Food allergens, especially milk and wheat, are the most common cause of anaphylaxis in children. Because anaphylaxis can be fatal, it is advisable to recognize its causes in different communities to prevent recurrent attacks.

Evaluation of CD11b expression on peripheral blood neutrophils for early detection of neonatal sepsis

Neonatal sepsis is a disease of infants who are less than 1 month of age. These infants are clinically ill, and their blood culture are positive for bacteria. The reported incidence of neonatal sepsis for all infants is 1 to 10 per 1000 live births. The mortality rate is 4.2-26%. The clinical signs are not specific and diagnosis of neonatal sepsis is one of the most difficult tasks in clinical medicine. The aim of this work was determination of CD11b sensitivity and specificity for early detection of neonatal sepsis. We studied 65 neonates with gestational age of 27 to 38 weeks who were suspected for sepsis within the 28 days of life. Whole blood was obtained from neonates to determine CD11b expression on peripheral blood neutrophils by flow cytometry. C-Reactive protein (CRP) was measured qualitatively. Neonates were divided into two groups. Classification was based on the result of the blood culture. In the sepsis group all of the neonates (n=8) showed positive blood culture and clinical symptoms. In the suspected group (n=57) the neonates showed clinical signs but blood cultures were negative. Sensitivity and specificity of CD11b were 75%, 100% respectively. Also positive and negative predictive values of CD11b were 100% and 86% respectively. Results of present study and previous studies showed that measurement of neutrophil surface markers can be useful for diagnosis of infection in the early phases. Also, the quantitative measurement of CRP in addition to CD11b further enhances the ability to diagnose infections and improves sensitivity and negative predictive value by 100%.

Bcl-2 associated athanogene-1 overexpression in diffuse large B-cell lymphoma

BACKGROUND

Apoptosis and cell cycle regulation play an important role in pathogenesis and tumor progression in patients with Diffuse Large B-Cell Lymphoma (DLBCL). Bcl-2 associated athanogene-1 (BAG-1) is an antiapoptotic protein as well as a regulator of cell growth. There is no conclusive evidence about BAG-1 protein expression in this disease.

OBJECTIVE

To investigate the expression level of BAG-1 protein in DLBCL.

METHODS

Thirty patients diagnosed from 1997-2004, as having DLBCL, were selected. Also 30 normal lymph nodes were included as normal counterparts in this study. BAG-1 expression was determined by immunohistochemical staining in both DLBCL and normal lymph node samples.

RESULTS

Of the 30 DLBCLs examined, 100% were positive for nuclear and 83% were positive for cytoplasmic BAG-1 staining. Of the 30 normal lymph nodes investigated, 20% were positive for nuclear and 0% were positive for cytoplasmic BAG-1 staining. Nuclear staining in DLBCL samples was significantly higher than those of normal lymph nodes (100% versus 20%, p <0.001). Besides, cytoplasmic staining in DLBCL samples was significantly higher than those of normal lymph nodes (83% versus 0%, p <0.001). There was no association between BAG-1 staining and patients' overall survival.

CONCLUSION

Our data indicated that BAG-1 protein was deregulated in this disease similar to some other malignancies such as breast and colon cancer. Overexpression of BAG-1 in DLBCL suggests that this protein probably plays an important role in the pathogenesis of DLBCL. Besides, higher nuclear BAG-1 staining might be correlated with poor prognosis.